This article looks at some ways of maximising the response of postal research - and its practical value.
A successful postal survey is one which achieves an accurate and high response. The design of the postal questionnaire is the key to that achievement and it requires the researcher to put herself into the position of the interviewee. Though she will not be present when the questionnaire is being completed, the researcher must be able to imagine the difficulties the respondent will face and take these into account in the formulation of the questions. So she must have a good feel for his subject; otherwise, when the replies come in, it may be found - too late – that there were silly mistakes in the questionnaire. Questionnaire design can be broken down into three steps which must be undertaken in chronological order – formulate the questions; arrange the questionnaire layout; and test the draft.
Formulating The Questions
The researcher should begin by making a rough list of all the points to which answers are required. The objectives of the survey are the guide. Thus, if one objective is to assess the market size, a question must be posed which establishes the respondent's purchases of products over a given period. If another objective is to measure the market shares of suppliers, a question must be asked on the respondent's source of purchases. The rough listing of questions should be comprehensive and may well include at least the following basics:
- What are the respondent's purchases of the product in volume and value per year?
- Who are the major suppliers and what share do they have of his supply?
- What is the image of suppliers?
- What factors influence his choice of supplier and how important are they?
- How are purchases likely to change in the future?
- What are the factors that will influence this change?
Clearly the list will be much longer as it will contain specific questions geared to the needs of the survey. Each of the questions in the rough listing should now be scrutinised to establish whether they are vital to the survey, since the longer the questionnaire, the lower will be the response.
The difficult job of converting the rough questions to ones which a respondent can answer must now be tackled. Simple and clear language should always be used. It must not be assumed, for example, that the respondent understands the meaning of words like salient or infrastructure. Ambiguities must be avoided like the plague. Words like frequent, good and useful need qualifying.
Questions should be precise and yet easy for the respondent to answer. Ease of response can be achieved by precoding, so that only a tick is required by way of answer. This use of multiple choices speeds the completion of the questionnaire and is useful in demonstrating to the respondent that an answer between broad limits is perfectly acceptable. The question "What are your company's purchases of steel?" may eventually end up as:
Please indicate with a tick in the appropriate boxes, your establishment's purchases of low and high carbon steel in the year 2000:
|Low Carbon (below 25%c)||High Carbon (over 25%c)|
|Less than 25 tonnes||[ ]||[ ]|
|25 - 50 tonnes||[ ]||[ ]|
|51 - 100 tonnes||[ ]||[ ]|
|101 - 500 tonnes||[ ]||[ ]|
|over 500 tonnes||[ ]||[ ]|
Table 1: Cost Of Mailing 1,000 Questionnaires
If an effort is made to judge the type of answer which might result from a question, pitfalls will be avoided. A question which simply asks "What do you think of Dormer as a supplier of twist drills?" may generate a vague response such as "very good". The researcher will be left wondering why they are considered very good. It is far better to pin the respondent down by providing a scale and introducing other companies as benchmarks. Hence the question becomes:
Rate the following suppliers for their speed of delivery, reliability of delivery, length of life and value for money, where:
- 5 - Excellent
- 4 - Good
- 3 - Neutral
- 2 - Poor
- 1 - Unacceptable
If you have no experience of a supplier, please score 6.
|Speed of Delivery||Reliability of Delivery||Length of Life||Value for Money|
In postal questionnaires, precoded questions are nearly always preferable. They make completion easier for the respondent and facilitate analysis.
Arranging The Questionnaire Layout
Questions need to be neatly formatted so that the questionnaire looks attractive and easy to complete.
Questions covering a specific subject, such as trends, suppliers or purchasers, should be grouped. Respondents should be taken gradually from simple to difficult (or delicate) questions in a logical order. Thus the first questions on the form are likely to ask easy to complete questions about purchasing behaviour. A simple routine question could then lead him into the body of the questionnaire.
By structuring the questionnaire from simple to the more difficult, the researcher is easing the respondent into his work. Once started, she will find a motivation to continue and finish. The embarrassing or controversial questions, left until the end, now stand a chance of completion.
Market research questionnaires are viewed by most as just another form and since there is no compulsion to respond there is a danger that they will end up in the waste paper basket unless the respondent has an incentive to reply. If the questionnaire is visually attractive it will help. It costs no more for the questionnaire to be printed on coloured paper. Not only does this look appealing, it helps stand out in the sea of white paper on most respondents' desks. Cartoons can give visual relief and again add interest.
Every attempt should be made to lay the questionnaire out on one piece of paper. It looks better and avoids stapled pages. Ideally the questionnaire should be restricted to two sides of A4, i.e. A3 folded so that there are four pages in booklet form.
Pilot Testing The Draft Questionnaire
The perfect questionnaire has yet to be written. When a draft has been prepared which appears acceptable to the researcher, it should be tried on at least two or three colleagues. Next the questionnaire should be tested in the field. Theoretically the test should be a small scale postal survey. However, the draft questionnaire is usually tested face to face amongst half a dozen target respondents who have the opportunity of saying what was in their minds as they completed each question.
Although the design of the questionnaire is the key element of a postal survey, the first thing seen by respondents is the covering letter. The aim of the cover letter is to persuade the recipient to give up time, exercise the mind and part with valuable information without any immediate or obvious reward.
The cover letter should attempt to bond the sender and respondent and so is likely to include liberal doses of the words you and we or I. The style of writing must be engaging so that the interest of the reader is held and yet it should also convey confidence that a reply will be put to good use.
The first paragraph, should explain the objectives of the research. No matter how vague, respondents need a hook or incentive for replying. This could be the promise of an improved service, increased efficiency, a more comprehensive range of products, etc. It should be explained that a reply is critical to the success of the survey and an assurance provided that the completion and response can be carried out quickly and easily. Finally, an offer of confidentiality should allay fears that there will be any future embarrassment or sales pressure.
Ninety per cent of the replies from the mail shot will be returned within two weeks of its dispatch. To increase the response a reminder could be mailed 14 days after the first shot.